1. Field of the Invention
The present invention relates to an information processing device, an information processing method, and a program, particularly to an information processing device, an information processing method, and a program capable of providing an estimation result with appropriate randomness.
2. Description of the Related Art
A technique of estimating, on the basis of the metadata of a known content item, the unknown metadata of another content item has been proposed in the past by the present applicant (see Japanese Unexamined Patent Application Publication No. 2007-122186, for example). This estimation of the metadata is used in, for example, recommendation processing of recommending the most suitable content to a user.
For example, in an example in which the content is music, machine learning for creating a metadata estimation formula on the basis of the feature quantity of a music piece is performed, and the feature quantity of a predetermined music piece is input to the metadata estimation formula created by the machine learning. Thereby, the unknown metadata of the music piece can be estimated. Herein, the feature quantity of a music piece refers to the value obtained by the calculation of the data (signal) of the music piece with the use of a predetermined feature quantity calculation formula. Further, the metadata of a music piece refers to the value representing a feature of the music piece corresponding to user perception of the music piece, such as cheerfulness, bittersweetness, sadness, and fast pace.
Therefore, if the estimated metadata includes “cheerfulness” representing the degree of cheerfulness of a music piece, and if a user searches for “cheerful” music pieces, for example, a search device can calculate (estimate) the degree of the metadata “cheerfulness” for each of content items stored by the user on the basis of the metadata estimation formula, and can present to the user music pieces sorted in descending order of the degree.
In this type of estimation of the metadata, however, the metadata of a music piece is estimated solely on the basis of the feature quantity of the music piece. Therefore, it is naturally difficult to estimate the metadata with 100% accuracy. That is, the estimation result usually includes an error. In the above-described case in which the user searches for “cheerful” music pieces, the presentation order of the presented “cheerful” music pieces includes an error. It is therefore difficult to guarantee that the presentation order truly reflects the order of “cheerful” music pieces.